I have just been informally keeping track of this over the weekend while pugging WZs. If I wind up in Alderaan and before the match say "Two - Left / Everyone Else Mid and then Hold- do not leave" Then make sure you have two people call out that they are going left (And make sure those people know to stay there and guard even if no one is actively attacking).---
We win.*
If I do not, people scatter like idiots and we lose. It's just a piece of advice for those who find that their Alderaan missions (In Pugs-- I grant you that premades probably don't have this issue).
I hope this helps.
*I do recognize that this is one of many strategies, but it is one I continue to see work.